kernel/uid16.c

   1 /*
   2  *      Wrapper functions for 16bit uid back compatibility. All nicely tied
   3  *      together in the faint hope we can take the out in five years time.
   4  */
   5
   6 #include <linux/mm.h>
   7 #include <linux/utsname.h>
   8 #include <linux/mman.h>
   9 #include <linux/smp_lock.h>
  10 #include <linux/notifier.h>
  11 #include <linux/reboot.h>
  12 #include <linux/prctl.h>
  13 #include <linux/capability.h>
  14 #include <linux/init.h>
  15 #include <linux/highuid.h>
  16 #include <linux/security.h>
  17 #include <linux/syscalls.h>
  18
  19 #include <asm/uaccess.h>
  20
  21 asmlinkage long sys_chown16(const char __user * filename, old_uid_t user, old_gid_t group)
  22 {
  23         return sys_chown(filename, low2highuid(user), low2highgid(group));
  24 }
  25
  26 asmlinkage long sys_lchown16(const char __user * filename, old_uid_t user, old_gid_t group)
  27 {
  28         return sys_lchown(filename, low2highuid(user), low2highgid(group));
  29 }
  30
  31 asmlinkage long sys_fchown16(unsigned int fd, old_uid_t user, old_gid_t group)
  32 {
  33         return sys_fchown(fd, low2highuid(user), low2highgid(group));
  34 }
  35
  36 asmlinkage long sys_setregid16(old_gid_t rgid, old_gid_t egid)
  37 {
  38         return sys_setregid(low2highgid(rgid), low2highgid(egid));
  39 }
  40
  41 asmlinkage long sys_setgid16(old_gid_t gid)
  42 {
  43         return sys_setgid(low2highgid(gid));
  44 }
  45
  46 asmlinkage long sys_setreuid16(old_uid_t ruid, old_uid_t euid)
  47 {
  48         return sys_setreuid(low2highuid(ruid), low2highuid(euid));
  49 }
  50
  51 asmlinkage long sys_setuid16(old_uid_t uid)
  52 {
  53         return sys_setuid(low2highuid(uid));
  54 }
  55
  56 asmlinkage long sys_setresuid16(old_uid_t ruid, old_uid_t euid, old_uid_t suid)
  57 {
  58         return sys_setresuid(low2highuid(ruid), low2highuid(euid),
  59                 low2highuid(suid));
  60 }
  61
  62 asmlinkage long sys_getresuid16(old_uid_t __user *ruid, old_uid_t __user *euid, old_uid_t __user *suid)
  63 {
  64         int retval;
  65
  66         if (!(retval = put_user(high2lowuid(current->uid), ruid)) &&
  67             !(retval = put_user(high2lowuid(current->euid), euid)))
  68                 retval = put_user(high2lowuid(current->suid), suid);
  69
  70         return retval;
  71 }
  72
  73 asmlinkage long sys_setresgid16(old_gid_t rgid, old_gid_t egid, old_gid_t sgid)
  74 {
  75         return sys_setresgid(low2highgid(rgid), low2highgid(egid),
  76                 low2highgid(sgid));
  77 }
  78
  79 asmlinkage long sys_getresgid16(old_gid_t __user *rgid, old_gid_t __user *egid, old_gid_t __user *sgid)
  80 {
  81         int retval;
  82
  83         if (!(retval = put_user(high2lowgid(current->gid), rgid)) &&
  84             !(retval = put_user(high2lowgid(current->egid), egid)))
  85                 retval = put_user(high2lowgid(current->sgid), sgid);
  86
  87         return retval;
  88 }
  89
  90 asmlinkage long sys_setfsuid16(old_uid_t uid)
  91 {
  92         return sys_setfsuid(low2highuid(uid));
  93 }
  94
  95 asmlinkage long sys_setfsgid16(old_gid_t gid)
  96 {
  97         return sys_setfsgid(low2highgid(gid));
  98 }
  99
 100 static int groups16_to_user(old_gid_t __user *grouplist,
 101     struct group_info *group_info)
 102 {
 103         int i;
 104         old_gid_t group;
 105
 106         for (i = 0; i < group_info->ngroups; i++) {
 107                 group = high2lowgid(GROUP_AT(group_info, i));
 108                 if (put_user(group, grouplist+i))
 109                         return -EFAULT;
 110         }
 111
 112         return 0;
 113 }
 114
 115 static int groups16_from_user(struct group_info *group_info,
 116     old_gid_t __user *grouplist)
 117 {
 118         int i;
 119         old_gid_t group;
 120
 121         for (i = 0; i < group_info->ngroups; i++) {
 122                 if (get_user(group, grouplist+i))
 123                         return  -EFAULT;
 124                 GROUP_AT(group_info, i) = low2highgid(group);
 125         }
 126
 127         return 0;
 128 }
 129
 130 asmlinkage long sys_getgroups16(int gidsetsize, old_gid_t __user *grouplist)
 131 {
 132         int i = 0;
 133
 134         if (gidsetsize < 0)
 135                 return -EINVAL;
 136
 137         get_group_info(current->group_info);
 138         i = current->group_info->ngroups;
 139         if (gidsetsize) {
 140                 if (i > gidsetsize) {
 141                         i = -EINVAL;
 142                         goto out;
 143                 }
 144                 if (groups16_to_user(grouplist, current->group_info)) {
 145                         i = -EFAULT;
 146                         goto out;
 147                 }
 148         }
 149 out:
 150         put_group_info(current->group_info);
 151         return i;
 152 }
 153
 154 asmlinkage long sys_setgroups16(int gidsetsize, old_gid_t __user *grouplist)
 155 {
 156         struct group_info *group_info;
 157         int retval;
 158
 159         if (!capable(CAP_SETGID))
 160                 return -EPERM;
 161         if ((unsigned)gidsetsize > NGROUPS_MAX)
 162                 return -EINVAL;
 163
 164         group_info = groups_alloc(gidsetsize);
 165         if (!group_info)
 166                 return -ENOMEM;
 167         retval = groups16_from_user(group_info, grouplist);
 168         if (retval) {
 169                 put_group_info(group_info);
 170                 return retval;
 171         }
 172
 173         retval = set_current_groups(group_info);
 174         put_group_info(group_info);
 175
 176         return retval;
 177 }
 178
 179 asmlinkage long sys_getuid16(void)
 180 {
 181         return high2lowuid(current->uid);
 182 }
 183
 184 asmlinkage long sys_geteuid16(void)
 185 {
 186         return high2lowuid(current->euid);
 187 }
 188
 189 asmlinkage long sys_getgid16(void)
 190 {
 191         return high2lowgid(current->gid);
 192 }
 193
 194 asmlinkage long sys_getegid16(void)
 195 {
 196         return high2lowgid(current->egid);
 197 }